This is working out quite well so far. Some rather unscientific timing tests indicate some performance gains too. Although the Compact Flash can not match the raw throughput of the hard drive, it must have lower seek/access times.

Ok, I am thinking at loud here. Perhaps you can make an udev rule to automount that device as swap when plugged. The first trouble is that could not be vl-hot friendly, but you could put the udev rule right on top of the vl-hot ones, and use the last_rule option to avoid the effect of vl-hot rules trying to mount the device too.http://reactivated.net/writing_udev_rules.html#external-run

USB flash swap is working now. I moved the USB stick to another port and it started working. Put it back in the original one and it kept working. Not sure what the issue was, but another lesson in "keep trying".

I am quite pleased with how this is turning out. For one thing, spreading the filesystem over three devices (CF, i-Ram and network), seems to have reduced some read/write bottlenecks. Right now I'm running a batch conversion of video files, reading and writing to network shares. One core is pegged at 100% and the second one bounces between 20 and 40. I tried some file copy operations between the local devices and they were quick. The desktop is very responsive, application launch is fast and browsing seems like it always does.

The next step will be to modify the case and replace the current cooling fans with one slow-turning 120 mm one.

Next phase is in testing. I removed the PSU and CPU fans. Using foam board, hot glue and the handyman's secret weapon, I built a box around the CPU/chipset area. There is a 120 mm variable speed fan right over the CPU/chipset heatsinks and the air if forced out through the PSU.

With the fan running at minimum (~ 700 RPM), during normal use the CPU is running around 28 degrees Celsius. That is about 5 degrees hotter than before. From what I can find, the "worry temperature" of this Northwood is 57. Under stress with both cores at 100% it reached this temp after 15 minutes (before, it would peg at 40). Increasing fan speed to 1100 RPM brings it down to 50. Dang, why didn't I put the temperature sensor on the bottom of the heat sink before putting everything together?!

At the minimum setting I can still hear the fan, but the constant and unvarying noise is a lot less noticeable than the variable hum and chatter of the hard drive. I'll run it like this for a few weeks before changing anything else.

Like with many other things in life, the last 20% gain takes 80% of the effort!

After getting the cooling fan so quiet that I could hardly hear any airflow noise, I became aware of the sound from the electric motor. An annoying, high pitch sound that would vary in pitch according to CPU usage.

I ended putting the fan back in the PSU (an automatic 135 mm fan, probably about as quiet as they come). I made some baffles so it would pull the air across the CPU heat sink, and it seems to be very effective. CPU now runs cooler than when I had a fan on it. Obviously, if I want it silent, I will need to go with a fanless PSU and one of those monster overclocking CPU heatsinks.

For most people who would want to reduce the noise of their machines, I think the greatest cost to return ratio would come from buying a high efficiency PSU ($60-100), which will also give you some power savings. Mounting a quiet fan ($10) over the CPU also gives good results with little effort.

I saw a article some time ago on the net about a guy who made a completely fan less system. It was a pump less water cooled system. The coolant would be sent to various parts of the computer and finally the power supply heatsink(s). As the coolant would heat up, it would create it's own flow. Was made completely from hardware store parts. With the exception of the cpu watercooled heatsink. Pretty neat stuff.

It has been nine months, I thought a long term update might be of interest.

The system is unchanged since last post. However, I had to make some small changes to my user habits. Without the seemingly unlimited storage capacity of the hard drive, I can no longer just dump everything into my home directory. Once used to saving ISO's and other large files to my network server, the machine acts and feels much like it did before. It remains a little faster, and almost silent. I can only hear it when no appliances are running and the (physical) windows are closed.

All in all, I have been very happy with the experiment. It was rather involved, combining a CF-card, an iRam, tmpfs, a network server and a gigabit LAN, but it was very rewarding putting it together and getting it to work.

I'm getting ready to build a new one, and plan to use the same setup on it. Hopefully the low-powered Intel Core 2 CPU's will be equally cool-running as the old Northwood.

My plans to upgrade the system got deferred as other projects took preference.

I am happy to see that hardware development has changed direction, now going towards smaller and more efficient, rather than just higher GHz numbers. I can see getting one of the fanless, SSD equipped mini-systems available.

However, as the current hardware still serves me well, I will be keeping it as it is for now. I finally upgraded from VL SOHO 5.8 to VL 6.0 Light. After adding KDE3 I'm ready to go for at least another year with it.

Some observations worth mentioning:

The i-Ram could have been improved by Gigabyte. For starters, using SATA-1 is a waste when the on-board RAM could fully take advantage of a SATA-2 connection. Second, the battery is a weak point. After a year and a half, I found mine bulging like a balloon. It still worked but was not very confidence inspiring. Obtaining a new one was neither easy nor cheap. I ended up having to contact Gigabyte customer support and special order a new one for $35 plus $8 s/h. I was tempted to hack together some other solution, but it has three contacts on it and two voltages, so I let that go for now. From what I can tell, it looks a lot like a Kodak KLIC-5001. I speculate that may be an option. Maybe later.

Only once did I lose some data when severe weather knocked my power out for three days in a row. After that I set my email clients to leave the mail on server for a few days, and tweaked my backup script to run more often.

NFS has replaced SAMBA for the network connection to my file server. It handles mount/umount better, integrates more seamlessly into the filesystem, and properly manages Linux file permissions. Write speeds jump around some but average about 26 MB/s. Read speeds are higher and more consistent, seem to match the performance of the hard drives on the server. I have seen read speeds over 50 MB/s.

I use XFS on all the local drives and have had no issues with that.

2 GB of RAM is sufficient, not once have I noticed any slowdowns that I could have attributed to running low on memory and usage of swap. I normally shut the machine down every night, so it gets a fresh start every morning.